At the University of Miami on Wednesday, Joe Biden had an odd fantasy. He declared that had he heard Donald Trump boasting about sexually assaulting women in high school, he would have taken “him behind the gym and beat the hell out of him.” Biden has said something similar before. He shouldn’t say it again.

The reason is obvious: America’s leaders shouldn’t glorify violence. It’s a point liberals have made many times since Trump’s political rise. They made it after Trump gestured to a protester at a Las Vegas rally in February 2016 and announced that, “I’d like to punch him in the face.” They made it in July 2017 when Trump tweeted an image of him body slamming and punching a man whose head was replaced by the CNN logo. They made it later that month after Trump encouraged police in Long Island to slam suspects’ heads against their police cars while taking them into custody. Again and again, liberals warned that Trump’s fantasies of violence could incite actual violence. And they have been proven right. A study published this month by researchers at the University of Pennsylvania found that when Trump held a campaign rally in a city, assaults went up.

The fact that Biden glorified violence in an attempt to display his antipathy toward sexual assault—rather than his antipathy toward protesters, criminals or journalists—doesn’t justify it. For starters, Biden’s comments actually disempower women. As Alyssa Rosenberg noted in The Washington Post, “The way Biden chose to puff himself up is a weird mirror of Trump’s own remarks on the ‘Access Hollywood’ tape: Both men were trying to prove their virility at someone else’s expense. In Trump’s case, that someone else was the women who, theoretically, will let a famous man do anything. In Biden’s, it was another man he boasted he could dominate. And in both scenarios, women and our rights are secondary to how men can use us.” Given Biden’s checkered history on the question of sexual assault—as reflected in his treatment of Anita Hill, for which he has since apologized—he’d do well to take Rosenberg’s critique to heart.

Secondly, Biden encouraged disrespect for the law. Survivors of sexual violence don’t need vigilantes. They need clear rules about what constitutes unacceptable conduct, and officials willing to enforce them. Biden’s comments oddly echoed the logic of antifa, the leftist group that has been violently confronting white nationalist gatherings: Because our enemies are vile, and our motives are pure, we can take the law into our hands.

Despite all this, many liberals will give Biden a pass because they think his macho language works. They think that by matching Trump’s tough-guy demeanor, he might win back some of the white working-class voters who deserted them in 2016. It’s part of a larger Trump mimicry that has taken hold among some progressives over the last eighteen months. Perhaps, some have reasoned, Democrats should nominate a billionaire or celebrity of their own. Perhaps they should give Trump demeaning nicknames. Perhaps they should use profanity. Perhaps they should adopt his position on trade.

Maybe these are smart strategies. Maybe not. That’s for Democratic consultants to decide. But it’s never a good idea for political writers to decide that the ends justify the means. If Trump isn’t qualified to run the country, then a Democratic celebrity with no political experience isn’t either. If Trump’s insults degrade public discourse, then so do Democratic insults. And if it’s wrong for Trump to egg on his fans by romanticizing violence, then it’s wrong for Joe Biden to do it too.

On Thursday morning on Twitter, Trump responded, predictably, that if they fought, Biden “would go down fast and hard, crying all the way.” It was a vain, stupid eruption, and Biden had it coming. If you behave like Trump, you forfeit your right to be outraged when Trump does too.